We are requesting funds to purchase a SARRP image-guided x-ray platform in order to continually support a total of 26 research projects. Among the currently funded projects that requires the use of the irradiator, nine of them are NIH RO1, one PO1 and one U-42 projects. Additionally, one funded FDA approved phase1/2 study and four NIH RO1 projects that are likely to get funded (currently under council review) proposed to use the irradiator. Apart from that, four other federally funded projects (US Department of Defense, Veteran Administration) and six state- or institutional-funded project depend on the irradiator use. The track record and productivity out of the current irradiator use is significant with seminal publications including the journals Nature, Mol. Cell Biol., J Biol. Chem., PNAS, and Cancer Research. As an added benefit, the irradiation facility is integrated with other institutional core facilities including institutional transgenic core platform. Currently the investigators perform their radiation exposures for biological samples in a Gamma Cell-40 irradiator which has been in use since 1980. As of March 2010, the manufacturer proclaimed this 35-year old 137Cs source irradiator an end-of-useful lifecycle and informed that the company can no longer guarantee replacement parts on this old unit. It periodically shows a faulty door-lock system and air pressure resulting in inappropriate positioning of the exposures heads or over exposure due to failure in unlocking the door. When safety system kicks-in, due to unsecured door locks, sometimes, system fails to switch on. In addition, since this decades-old equipment has no provision for partial body irradiation or targeted delivery, it is unable to meet the requirements of several current and newly approaching research studies. Unlike the old irradiator SARRP 200 can be used for animals other than mice. Built-in immobilization system allows the users to expose the animals under anesthetic condition which is not possible with the current irradiator. The SARRP image guided irradiator platform has no radioactive source and is designed specifically as Cs replacement for biological research. Additionally, SARRP has several advantageous over its principal commercial competitors. The SARRP 200 irradiation system is chosen for its performance more suited for the current and future users, wide use in several laboratories, safety, durability, self-shielding, and its useful life time. We have a carefully constituted an internal advisory committee for a productive operation of the irradiator for an extended period of time. With a strong institutional support and technical expertise by running the irradiator for the past several years we are confident that we can diligently operate the irradiator and support the current projects and meet the challenges/ requirements of incoming studies in future. Both physicians from the Medical School and the NCI designated Cancer Therapy Research Center (CTRC), and translational/basic scientists with multiple NIH projects from UTHSCSA Graduate School of Biomedical Sciences can take full advantage of this equipment.